title: A role for glutathione, independent of oxidative stress, in the developmental toxicity of methanol.
abstract: Oxidative stress and reactive oxygen species (ROS) have been implicated in the teratogenicity of methanol (MeOH) in rodents, both in vivo and in embryo culture. We explored the ROS hypothesis further in vivo in pregnant C57BL/6J mice. Following maternal treatment with a teratogenic dose of MeOH, 4 g/kg via intraperitoneal (ip) injection on gestational day (GD) 12, there was no increase 6h later in embryonic ROS formation, measured by 2',7'-dichlorodihydrofluorescin diacetate (DCFH-DA) fluorescence, despite an increase observed with the positive control ethanol (EtOH), nor was there an increase in embryonic oxidatively damaged DNA, quantified as 8-oxo-2'-deoxyguanosine (8-oxodG) formation. MeOH teratogenicity (primarily ophthalmic anomalies, cleft palate) also was not altered by pre- and post-treatment with varying doses of the free radical spin trapping agent alpha-phenyl-N-tert-butylnitrone (PBN). In contrast, pretreatment with L-buthionine-(S,R)-sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, depleted maternal hepatic and embryonic GSH, and enhanced some new anomalies (micrognathia, agnathia, short snout, fused digits, cleft lip, low set ears), but not the most common teratogenic effects of MeOH (ophthalmic anomalies, cleft palate) in this strain. These results suggest that ROS did not contribute to the teratogenic effects of MeOH in this in vivo mouse model, in contrast to results in embryo culture from our laboratory, and that the protective effect of GSH in this model may arise from its role as a cofactor for formaldehyde dehydrogenase in the detoxification of formaldehyde.
authors.affiliation: Division of Biomolecular Sciences, Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Michelle T
authors.initials: MT
authors.lastname: Siu
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Shapiro
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Wiley
authors.forename: Peter G
authors.initials: PG
authors.lastname: Wells
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000445:Aldehyde Oxidoreductases / Q000494:pharmacology; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003497:Cyclic N-Oxides / Q000494:pharmacology; D004249:DNA Damage / Q000187:drug effects; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005609:Free Radicals / Q000378:metabolism; D005978:Glutathione / Q000494:pharmacology*; D008297:Male; D000432:Methanol / Q000633:toxicity*; D008717:Methionine Sulfoximine / Q000031:analogs & derivatives / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D018384:Oxidative Stress / Q000187:drug effects*; D011247:Pregnancy; D017382:Reactive Oxygen Species / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D013723:Teratogens / Q000633:toxicity
chemical_list: D003497:Cyclic N-Oxides; D005609:Free Radicals; D017382:Reactive Oxygen Species; D013723:Teratogens; C065566:buthionine sulfoximine ethyl ester; D008717:Methionine Sulfoximine; C029217:phenyl-N-tert-butylnitrone; D000080242:8-Hydroxy-2'-Deoxyguanosine; D000445:Aldehyde Oxidoreductases; C087006:formaldehyde dehydrogenase, glutathione-independent; D003849:Deoxyguanosine; D005978:Glutathione; D000432:Methanol
keywords: 2′,7′-dichlorodihydrofluorescin diacetate; 5,5′-dithiobis-(2-nitrobenzoic acid); 8-oxo-2′-deoxyguanosine; 8-oxodG; ADH1; ADH3; BSO; DCFH-DA; DMSO; DTNB; EtOH; FA; Formaldehyde; GD; GSH; GSSG; Glutathione; H(2)O(2); HNE; HPLC; LC–MS/MS; MeOH; Methanol; NADPH oxidase; NF-κB; NOX; NTD; NZW; Na-FA; New Zealand White rabbits; Oxidative stress; PBN; RFU; ROS; Reactive oxygen species; Teratogenesis; alcohol dehydrogenase; alpha-phenyl-N-tert-butylnitrone; dimethyl sulfoxide; ethanol; formaldehyde dehydrogenase; formic acid; gestational day; high-performance liquid chromatography; hydrogen peroxide; hydroxynonenal; intraperitoneal; ip; l-buthionine-(S,R)-sulfoximine; liquid chromatography with tandem mass spectrometry; methanol; neural tube defect; nuclear factor transcription factor kappa-B; oxidized glutathione; reactive oxygen species; reduced glutathione; relative fluorescence units; sodium formate